Identify the cause of bleeding in all cases at least by gastroscopy and, if necessary, by colonoscopy. The exceptions are the following:
The cause of bleeding is evident on the basis of earlier investigations.
The general condition of a terminally ill patient is so poor that no active treatment is planned.
Definition
Black, tar-like stools indicate the mixing of blood with the contents of the bowel. If fresh blood or clots are visible in the faeces, see the article on rectal bleeding (haemorrhagia ex ano) Diseases Causing Rectal Bleeding.
Aetiology
The most common causes of melena are
duodenal ulcer
gastric ulcer or erosion
bleeding from the colon
oesophageal varices and ulcerations
bleeding from the small intestine
tumours.
Urgency of investigations and treatment
If the patient has symptoms resulting from low haemoglobin concentration or hypovolaemia (collapse, dizziness, vertigo, exacerbation of heart failure) the bleeding has been profuse, and the patient should be referred immediately. Correction of hypovolaemia with Ringer's solution is often indicated during transportation (not if the patient has heart failure).
A haemoglobin concentration under 80 g/l is usually an indication for red cell transfusion.
If the patient is asymptomatic, and the haemoglobin concentration is above 100 g/l the patient can be referred the following morning after a telephone consultation. However, follow-up in a hospital should be arranged immediately if there is any doubt.
The first investigation is always gastroscopy. If it is probable that the bleeding will continue the patient should be referred to a hospital where endoscopic treatment or surgery can be performed. If the cause of the bleeding is not revealed by gastroscopy and the bleeding is profuse, a CT angiography should be performed and, if needed, an interventional radiologist may occlude the bleeding blood vessel by coiling. Gastroscopy may be available in primary care or at an outpatient clinic, and the optimal place for the examination should be determined by assessing the patient's condition and the risk of continuous bleeding.
Colonoscopy can be performed at a general practice clinic provided that appropriate equipment and skills are available.